From a quarter to half of Earth’s vegetated lands has shown significant greening over the last 35 years largely due to rising levels of atmospheric carbon dioxide, according to a new study published in the journal Nature Climate Change on April 25.

An international team of 32 authors from 24 institutions in eight countries led the effort, which involved using satellite data from NASA’s Moderate Resolution Imaging Spectrometer and the National Oceanic and Atmospheric Administration’s Advanced Very High Resolution Radiometer instruments to help determine the leaf area index, or amount of leaf cover, over the planet’s vegetated regions. The greening represents an increase in leaves on plants and trees equivalent in area to two times the continental United States.

That last sentence bears repeating. Satellite records show an increase in leafy vegetation equal to twice the area of the continental United States. The scientists, Zhu et al. (2016), estimate that about 70% of the increase is due to carbon dioxide (CO2) emissions. You know, the same emissions climate activists call “carbon pollution.”

Check out NASA’s composite image of changes in “leaf area index” (LAI) based on three long-term satellite records:

The new study may be the most accurate of its kind to date, but previousstudies reveal the same big picture: a planet becoming greener, chiefly due to CO2 emissions.

Yet the Obama administration purports to estimate the “social cost of carbon” (SCC) — the alleged net damage of an incremental ton of CO2 emissions — using three computer models of which two, known as DICE and PAGE, have no significant CO2 fertilization benefit.

SCC analysis depends on too many arbitrary inputs to guide policymaking, as MIT Professor Robert Pindyk explains. Indeed, as actually practiced in the political arena, SCC analysis is computer-aided sophistry — a numbers game designed to make carbon energy look unaffordable no matter how cheap, and renewables look like a bargain at any price.

But even if carbon’s social cost could be divined by computer models, the administration would still have no excuse to use DICE and PAGE. Those models include only the potential negative impacts of CO2 emissions and omit the actually measured benefits. They are structurally biased. As such, they are unfit for use in regulatory development or justification.